Fest then embarked on his biography of Adolf Hitler, published in 1973. The first major biography of Hitler since that of
Alan Bullock in 1952 and the first by a German writer, it appeared at a time when the younger generation of Germans was confronting the legacy of the Nazi period. It sparked controversy among German historians, because Fest, a political conservative, rejected the then dominant view that the causes of Hitler's rise to power had been largely economic. He instead believed that the Third Reich's rise to power was the result of millions of Germans turning a blind eye to Hitler or actively supporting him. Fest explained Hitler's success in terms of what he called the "great fear" that had overcome the German middle classes, as a result not only of
Bolshevism and
First World War dislocation but also more broadly in response to rapid modernization, which had led to a romantic longing for a lost past. That led to resentment of other groups, especially Jews, which were seen as agents of modernity. It also made many Germans susceptible to a figure such as Hitler who could articulate their mood. "He was never only their leader, he was always their voice... the people, as if electrified, recognised themselves in him". In 1977, Fest directed a documentary entitled
Hitler: A Career. Fest's film, which aimed to explain why ordinary people in Germany loved Hitler, created some controversy among some critics such as the American historian
Deborah Lipstadt, who wrote that by featuring extensive clips of Hitler from propaganda films and totally ignoring the
Holocaust, Fest had engaged in the glorification of a murderer. Fest served as the editorial aide for
Albert Speer, Hitler's court architect and later Minister for Munitions, while Speer worked on his autobiography,
Inside the Third Reich (1970). After Speer's death, amid controversy over the reliability of the memoirs, Fest wrote
Speer: The Final Verdict (2002) in which he criticized Speer for deliberate complicity in the crimes of the Nazi regime, which Speer had successfully concealed during the
Nuremberg Trials. Fest wrote his other major work on German history, ''
Plotting Hitler's Death: The German Resistance to Hitler'' (1994), to mark the 50th anniversary of the
20 July plot to assassinate Hitler. This work marked a partial reconsideration of his earlier harsh verdict on the German people. He acknowledged that many Germans had opposed the Nazi regime within the limits imposed on them by their circumstances. He maintained his view, however, most Germans had willfully refused to accept the truth about Nazism until it was too late. In 2002, Fest published ''
Inside Hitler's Bunker: The Last Days of the Third Reich'', a work that was based in part on available evidence following the opening of the Soviet archives but largely confirmed the account of Hitler's death given in
Hugh Trevor-Roper's book
The Last Days of Hitler (1947). ''Inside Hitler's Bunker'', along with the memoirs of Hitler's personal secretary
Traudl Junge, provided the source material for the 2004 German film
Der Untergang (
Downfall), the third
postwar German feature film to depict Hitler directly. ==Career in journalism and criticism==